Compact display flex and driver sub-assemblies

ABSTRACT

Compact sub-assemblies of flexible circuits and drivers are provided. The sub-assemblies can occupy less space in an electronic device than conventional sub-assemblies. In one or more embodiments of the present invention, the flexible circuits can be attached to or wires can be disposed on portions of the substrate that previously were unoccupied in conventional sub-assemblies. In one or more embodiments, the sub-assemblies of the present invention also can have wires disposed underneath the driver or vary the width of the wires. In one or more embodiments, the sub-assemblies of the present invention also can have composite wires that occupy less space than wires of conventional sub-assemblies, while still maintaining similar energy flux.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.11/650,133, filed on Jan. 5, 2007, now allowed, which is herebyincorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to compact flexible circuit and driversub-assemblies for an electronic device.

BACKGROUND OF THE INVENTION

Many currently available electronic devices have displays that providegraphics to the user. To drive pixels of the display, a conventionaldisplay assembly can incorporate a display driver operatively coupledvia wires to a flexible circuit. The flexible circuit (also referred toherein as a “flex”) can be operatively coupled to a circuit board of theelectronic device using, e.g., board-to-board connectors. The circuitboard can have a controller for generating signals that instruct thedisplay driver to selectively drive pixels of the display.

Consumers are demanding increasingly smaller electronic devices withincreasingly larger displays. Consequently, space within the devices hasbecome increasingly limited. In particular, the size of the electronicdevice and display can be limited, in part, by the space occupied by thedisplay driver, the flex, and the wires that operatively couple the twocomponents.

SUMMARY OF THE INVENTION

The present invention can include compact flex and driver sub-assembliesfor an electronic device. The compact sub-assemblies can reduce theamount of space occupied by the flex, the driver, and the wires thatoperatively couple the two components.

In one or more embodiments of the present invention, this can beaccomplished by providing a flex with one or more attachment portionsthat attach to previously unused areas on a substrate on which thedriver is disposed. This can reduce or eliminate the areas of thesubstrate to which the flex used to be attached in conventional designs.For example, in conventional display assemblies, some areas of thesubstrate disposed laterally adjacent to the driver may not be occupiedby other components. Thus, the flex can be attached to those areas ofthe substrate. Wires can be disposed in a multi-dimensional (e.g., 2-Dor 3-D) pattern on the substrate to operatively couple the driver toportion(s) of the flex attached to the substrate.

In one or more embodiments of the present invention, the space withinthe electronic device occupied by the flex and driver sub-assembly canbe reduced by reducing the maximum width of the flex to be less thanthat of the driver. To evenly distribute and balance the signal linesacross the entire width of the driver, one or more of the wires thatoperatively couple the flex to the driver can be run underneath thedriver. Thus, at least one wire can be disposed in an area of thesubstrate on which the driver also is to be disposed, directly orindirectly.

Another embodiment of the present invention can include staggered wirelayouts that facilitate coupling of a flex to a substrate when the wireson both components are riot co-linearly disposed with each other at ornear the regions in which the two components are attached.

Another embodiment of the present invention also can includesub-assemblies having wires with widths that vary from wire to wire,and/or that vary along the same wire. This can permit a wire to betailored for specific impedance levels, while accommodating the limitedsurface area on which the wires can be disposed.

Another embodiment of the present invention also can include compositewires that deliver similar energy flux as multiple wires in conventionalsub-assemblies, but that occupy less space. This can permit the flex tohave a narrower width and/or for the wires to occupy less space on thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages of the present invention will be apparentupon consideration of the following detailed description, taken inconjunction with accompanying drawings, in which like referencecharacters refer to like parts throughout, and in which:

FIGS. 1A-1B show a prior art display assembly having a flex and driversub-assembly;

FIGS. 2A-2B illustrate a compact flex and driver sub-assembly inaccordance with a first embodiment of the present invention;

FIG. 3 illustrates a compact flex and driver sub-assembly in accordancewith a second embodiment of the present invention;

FIG. 4 illustrates a compact flex and driver sub-assembly in accordancewith a third embodiment of the present invention;

FIG. 5 illustrates a compact flex and driver sub-assembly in accordancewith a fourth embodiment of the present invention;

FIG. 6 illustrates a compact flex and driver sub-assembly in accordancewith a fifth embodiment of the present invention; and

FIGS. 7A-7C illustrate a staggered wire pattern in accordance with oneembodiment of the present invention;

FIG. 8 illustrates a wire pattern in accordance with one embodiment ofthe present invention;

FIG. 9A illustrates prior art wires used in conventional flex and driversub-assemblies;

FIGS. 9B-9D show illustrative composite wires in accordance with one ormore embodiments of the present invention; and

FIG. 10 shows illustrative electronic devices in which flex and driversub-assemblies of the present invention can be incorporated.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1A-1B show a prior art display assembly having a flex and driversub-assembly. Display assembly 10 can include pixel activation substrate12, color filter substrate 14, polarizing substrates 16, driver 18, andflex 20. Pixel activation components and color filters can be interposedbetween substrates 12 and 14. Color filter substrate 14 can be disposedon top of pixel activation substrate 12. Polarizing substrates 16 cansandwich pixel activation substrate 12 and color filter substrate 14therebetween. These stacking arrangements are merely illustrative.

Pixel activation components can include components that energize and/ordefine one or more pixels in the display. For example, in active liquidcrystal displays, pixel activation components can include a matrix ofthin film transistors that can energize liquid crystals in the display.The area in which the pixel activation components are disposed candefine active area 22 of the display in which graphics can be providedto users. Display assembly 10 also can include pixel active componentsfor other types of display technologies, e.g., passive liquid crystaldisplays, plasma displays, organic light emitting diode displays,surface-conduction electron emitter displays, or any other type ofdisplay technology known in the art or otherwise.

In conventional display assembly 10, pixel activation substrate 12 canhave driver ledge 24 on which display driver 18 and flex 20 aredisposed, directly or indirectly. To drive pixel activation componentsof display assembly 10, display driver 18 can be operatively coupled tothe pixel activation components via driver-to-active area fan-out 26.Fan-out 26 can include a set of wires disposed on pixel activationsubstrate 12, directly or indirectly. Display driver 18 can be driven bysignals transmitted through flex 20, which can be operatively coupled todriver 18 using flex-to-driver fan-out 28. Fan-out 28 also can include aset of wires disposed on pixel activation substrate 12, directly orindirectly. Flex 20, in turn, can be operatively coupled to a circuitboard (not shown) that generates signals for instructing driver 18 toselectively drive pixels of the display.

In conventional flex and driver sub-assemblies, flex 20 and driver 18can communicate using parallel signal transmission. The width of theportion of flex 20 attached to driver ledge 24 typically can be greaterthan or substantially equal to the width of driver 18 to permitflex-to-driver fan-out 28 to have a sufficient number of wires forparallel signal transmission. In conventional display assembly 10, thelength, cross-sectional area, and material of all, the wires offlex-to-driver fan-out 28 are substantially uniform so that each wire infan-out 28 has substantially the same nominal impedance. The nominalimpedance can be based on the maximum specified impedance for thesignals transmitted between driver 18 and flex 20.

The conventional design illustrated in FIGS. 1A-1B can suffer somedisadvantages. First, driver ledge 24 can have areas that are notoccupied by any components of the flex-to-driver sub-assembly. This canbe an inefficient use of space. Second, due to the configuration offlex-to-driver fan-out 28 and the consequent width of flex 20, the flexcan occupy a lot of space within the electronic device. Unfortunately,as electronic devices become smaller and displays become larger, thespace occupied by display driver 18, flex 20, and flex-to-driver fan-out28 can limit the small size of the electronic device and/or the size ofthe display.

In one or more embodiments, the present invention can reduce the amountof space occupied by driver 18, flex 20, and flex-to-driver fan-out 28and provide compact flex and driver sub-assemblies for electronicdevices generally.

FIGS. 2A-2B illustrate a compact flex and driver sub-assembly inaccordance with a first embodiment of the present invention.Sub-assembly 30 can include driver 32, flex 34, flex-to-driver fan-out36, and driver-to-active area fan-out 38, all of which can be disposed(at least in part) on driver ledge 40 of pixel activation substrate 42,directly or indirectly. In one embodiment of the present invention,substrate 42 can be made of transparent, non-conductive material, e.g.,glass.

To reduce the Y dimension of the driver ledge so that length Y₂ of ledge40 is less than length Y₁ of ledge 24 of FIG. 1, the space on driverledge 42 occupied by portions of flex 20 and fan-out 28 in conventionaldisplay assembly 10 can be reduced or eliminated. This can beaccomplished by attaching multiple smaller attachment portions 44 offlex 34 to areas of substrate 42 that were unused in conventionaldisplay assembly 10, instead of attaching the flex to the pixelactivation substrate along the entire width of the flex as in FIG. 1.For example, in conventional display assembly 10 of FIG. 1, unused areasof substrate 12 can be located laterally adjacent to driver 18 in theX-axis, e.g., in-line with longitudinal axis L1 of display driver 18. Toefficiently use this space, attachment portions 44 of flex 34 can bedisposed on substrate 42 in those previously unoccupied areas, e.g., sothat attachment portions 44 intersect longitudinal axis L1 of driver 32.As a result, flex 34 can form recess 46 between attachment portions 44within which driver 32 can be disposed.

Wires of flex-to-driver fan-out 36 can emanate from a single edge ofeach attachment portion 44 (as in FIG. 2A) or from multiple edges ofeach attachment portion 44 (as in FIG. 2B). In the latter case, thewires in attachment portion 44 and fan-out 36 can terminate in staggeredconfigurations, as described in greater detail below with respect toFIGS. 7A-7C. The wires also can terminate along one or more edges ofdisplay driver 32. Unlike the fan-out of conventional display assembliesin which all the wires are disposed in one-dimensional patterns, one ormore wires of fan-out 36 can be configured in a multi-dimensional (e.g.,2-D or 3-D) pattern. Advantageously, the flexibility in theconfiguration of the wires of flex-to-driver fan-out 36 can permit theflex and display driver sub-assemblies to be designed more compactly.

As used herein, when a wire is disposed in a one-dimensional pattern,that wire has a linear configuration. That is, the wire is disposed onthe substrate along one linear axis. When a wire is disposed in a 2-Dpattern, the wire has a non-linear configuration. For example, as shownin FIG. 2B, wire W is disposed on substrate 42 along both orthogonal Xand Y axes. A wire also can be disposed in a 2-D pattern when it isdisposed in two or more non-orthogonal directions. Likewise, a wire alsocan be disposed in a non-linear 3-D pattern.

Again, to efficiently use areas of the substrate that previously wasunoccupied in conventional flex and driver sub-assemblies, portions offlex-to-driver fan-out 36 may be disposed in the same lateral space inthe X-axis as driver-to-active area fan-out 38. For example, in theillustrative embodiment shown in FIGS. 2A-2B, no intervening componentsare disposed between the two fan-outs. Depending on the layout, the areaoccupied by driver-to-active area fan-out 38 and the configuration ofwires in fan-out 38 may need to be adjusted to accommodateflex-to-driver fan-out 36.

Because some of the wires of fan-out 36 have greater length than that ofthe wires of conventional flex-to-driver fan-outs, the longerwire-traces of fan-out 36 also may have greater impedance. To reduce thelikelihood that the impedances of the wires of flex-to-driver fan-out 36do not surpass the maximum specified impedance of the signalstransmitted therethrough, one or more of the wires can have a greatercross-sectional area than that of conventional flex-to-driver fan-outs.More detailed discussion of this can be found below with respect to FIG.8. To accommodate the greater cross-sectional area of one or more of thewires, flex-to-driver fan-out 36 can have a fewer number of wires ascompared to that of fan-out 28 of conventional display assembly 10. Totransmit the same number and type of signals with fewer wires, theelectronic device may employ a high speed serial interface, such as, forexample, the Mobile Pixel Link physical layer offered by NationalSemiconductor Corporation of Santa Clara, Calif., the Mobile DisplayDigital Interface offered by Qualcomm Incorporated of San Diego, Calif.,and the Mobile Industry Processor Interface (MIPI) promulgated by theMIPI Alliance. To further reduce the likelihood that the impedances ofthe wires of flex-to-driver fan-out 36 do not surpass the maximumspecified impedance of the signals transmitted therethrough, the signalscan be prioritized so that those requiring lower impedance wires can betransmitted through the wires having shorter length and/or largercross-sectional area.

Pixel activation substrate 42 can include additional features tofacilitate alignment of flex 34 and driver 32. For example, to alignflex 34, an optical registration camera (not shown) can be placedunderneath substrate 42 and used to provide feedback as to the alignmentof one or more registration marks on the substrate with one or moreregistration marks on the flex. Similarly, to align driver 32, theoptical registration camera can provide feedback as to the alignment ofone or more registration marks on the substrate with one or moreregistration marks on the driver. The optical registration camera alsocan be used to provide feedback as to the alignment of wires on the flexwith those of fan-out 36, and/or the alignment of electrical contacts ofdriver 32 with the wires of fan-out 36.

FIG. 3 illustrates a compact flex and driver sub-assembly in accordancewith a second embodiment of the present invention. Flex and driversub-assembly 50 can include driver 52, flex 54, flex-to-driver fan-out56, and driver-to-active area fan-out 58, all of which can be disposed(at least in part) on driver ledge 60 of pixel activation substrate 62,directly or indirectly.

To reduce the space within the electronic device that is occupied byflex 54, flex 54 can have a maximum width that is less than that of flex20 of FIG. 1 and driver 52 (i.e., maximum width X₅₄ of flex 54 can beless than width X₅₂ of driver 52). Because flex 54 has a smaller width,the area of flex 54 that can be attached to pixel activation substrate62 also can be smaller. As a result, flex 54 may not be able toaccommodate as many wires. Again, a high speed serial interface may beemployed to permit all desired signals to be transmitted using fewerwires. Composite wires, such as those described below with respect toFIGS. 9B-9D, also can be used to accommodate the reduction in the numberof wires. Also, to reduce the likelihood that the impedances of thewires of flex-to-driver fan-out 56 do not surpass the maximum specifiedimpedance of the signals transmitted therethrough, the wires of fan-out56 can have an increased cross-sectional area and signals can beprioritized so that those requiring lower impedance wires can betransmitted through the wires having shorter length and/or greatercross-sectional area.

As with flex-to-driver fan-out 36 of FIGS. 2A-2B, the wires offlex-to-driver fan-out 56 can emanate from a single edge of flex 54 orfrom multiple edges of flex 54. Some wires of fan-out 56 can have thesame uniform length and be disposed in a parallel one-dimensionalpattern between driver 52 and flex 54. These wires can transmit, forexample, signals that require transmission along lower impedance lines.Other wires can have non-uniform lengths and be disposed in 2-Dpatterns. These wires can transmit, for example, signals that permittransmission through higher impedance lines. Again, the flexibility inthe configuration of the wires of flex-to-driver fan-out 56 can permitflex and driver sub-assemblies to be designed to be more compact.

To reduce the Y dimension of the driver ledge so that length Y₃ of ledge60 is less than length Y₁ of ledge 24 of FIG. 1, one or more wires offlex-to-driver fan-out 56 can be routed underneath display driver 52when the driver is disposed on substrate 62. Thus, at least one wiretrace is disposed in an area of the substrate on which display driver 52is to be disposed, rather than occupying additional space on substrate62 in the X-Y plane. Depending on the height of the wires of fan-out 56,the wires disposed underneath driver 52 may not appreciably increase theheight by which the driver is offset from substrate 62. Wires routedunderneath driver 52 can transmit any type of power and data signals, solong as the resistance of the wires do not exceed the maximum impedancefor which the signals are specified. In one embodiment of the presentinvention, wires routed underneath the driver can transmit power signalsand/or serve as a ground potential.

FIG. 4 illustrates a compact flex and driver sub-assembly in accordancewith a third embodiment of the present invention. Flex and driversub-assembly 70 can include driver 72, flex 74, flex-to-driver fan-out76, and driver-to-active area fan-out 78 disposed on driver ledge 80 ofpixel activation substrate 82, directly or indirectly.

Sub-assembly 70 can be a combination of sub-assemblies 30 and 50. Forexample, flex 74 can have maximum width X₇₄ that is less than width X₇₂of driver 72. Because flex 74 is narrower, the attachment portion offlex 74 for attaching the flex to substrate 82 also may be smaller. Thiscan permit flex 74 to be attached to previously unused portions ofsubstrate 82. For example, flex 74 can be attached to substrate 72 sothat the flex intersects the longitudinal axis of driver 72.

Flex-to-driver fan-out 76 also can be configured similarly to those ofsub-assemblies 30 and 50. Flex-to-driver fan-out 76 can have wires thatemanate from one or multiple edges of flex 74. The wires also canterminate along one or multiple edges of display driver 72. One or morewires of fan-out 76 also can be disposed on substrate 82 in the samearea on which display driver 72 is disposed. That is, wires can bedisposed on substrate 82 underneath display driver 72. To accommodatesignals that require transmission along lower impedance lines, somewires of fan-out 76 can have the same uniform length and be disposed inparallel one-dimensional patterns between driver 72 and flex 74. Fan-out76 also can have one or more wires that are disposed in two-dimensionalpatterns. One or more two-dimensional wires in flex-to-driver fan-out 76can be disposed adjacent to driver-to-active area fan-out 78 in theX-axis.

FIG. 5 illustrates a compact flex and driver sub-assembly in accordancewith a fourth embodiment of the present invention. Flex and driversub-assembly 90 can be similar to sub-assembly 70 of FIG. 4 except thatmaximum width X₉₄ of flex 94 attached to substrate 102 can be greaterthan that of flex 72, while still being less than width X₉₂ of displaydriver 92. The added width can permit flex-to-driver fan-out 96 toincorporate additional wires for transmission of signals between driver92 and flex 94. This can permit an electronic device incorporatingsub-assembly 90 to employ either a parallel or serial data transmissioninterface as desired. Furthermore, the additional wires can have shorterlength and be disposed in parallel one-dimensional patterns between thedisplay driver and the flex. This can permit fan-out 96 to accommodatemore signals requiring transmission through lower impedance lines.

FIG. 6 illustrates a compact flex and driver sub-assembly in accordancewith a fifth embodiment of the present invention. Flex and driversub-assembly 110 can be similar to sub-assembly 30 of FIGS. 2A-2B exceptthat the mid-span of flex 34 can be eliminated to reduce the spaceoccupied by the flex. Accordingly, sub-assembly 110 can have two flexes114 and 116, each of which can be attached to substrate 126 atpreviously unoccupied areas of the substrate. Flex-to-driver fan-outs118, 120 can be disposed on substrate 126 (directly or indirectly) tooperatively couple each flex 114, 116 to driver 112. Each flex 114, 116also can have board-to-board connector 122, 124 for operatively couplingeach flex to a circuit board (not shown) of the electronic device.

FIGS. 7A-7C illustrate a staggered wire pattern in accordance with oneembodiment of the present invention. Flex 130 can be configured to beoperatively coupled to side-connecting flex-to-driver fan-out 139. Thatis, side-connecting flex-to-driver fan-out 139 can have at least onewire that emanates from flex 130 in a direction that is not parallel tothe longitudinal axis L2 or co-linear with the wires of flex 130 at ornear the regions in which fan-out 139 connects to flex 130. For example,fan-out 139 can have at least one wire that emanates from flex 130 in anorthogonal direction.

Flex 130 can include a substrate on which a set of wires 132, 134 aredisposed, directly or indirectly. Each wire 132, 134 can have at leasttwo termination regions, one disposed at one end of flex 130 and anotherdisposed at the other end of flex 130. One or more electrical contactscan be positioned at each termination region, as discussed in greaterdetail below with respect to FIGS. 9B-9D. The electrical contacts canoperatively couple flex 130 to other electrical components, e.g., thewires of a flex-to-driver fan-out or another circuit board, eitherdirectly or indirectly.

FIGS. 7A-7C illustrate the end of flex 130 that is configured forcoupling to pixel activation substrate 136 of a display assembly. Wires134 of flex 130 can have electrical contacts disposed in a staggeredconfiguration, whereas wires 132 of flex 130 can have electricalcontacts disposed in a non-staggered configuration.

Substrate 136 can have flex-to-driver fan-out 139 with wires disposed ina pattern that complements wires 132, 134 of flex 130. That is, theelectrical contacts of flex-to-driver fan-out 139 can be disposed onsubstrate 136 in positions that complement the positions at which theelectrical contacts of wires 132, 134 are disposed. For example, theelectrical contacts of wires 142 of flex-to-driver fan-out 139 can bedisposed in a complementary staggered configuration, whereas theelectrical contacts of wires 140 of the fan-out can be disposed in acomplementary non-staggered configuration. Electrical contacts disposedat the other ends or termination regions of wires 140, 142 can beoperatively coupled to electrical contacts on driver 138.

Advantageously, the staggered configurations of wires 134, 142 canfacilitate connection of a flex to a fan-out when the wires of thefan-out are not disposed co-linearly with the wires of the flex near theregions in which the two components connect. For example, as shown inFIGS. 7A-7C, the staggered configurations can facilitate connection of aflex having wires that are disposed orthogonal to the wires offlex-to-driver fan-out 139. While FIGS. 7A-7C illustrate flex 130 andflex-to-driver fan-out 139 as having wires with electrical contactsdisposed in both staggered and non-staggered configurations, flex 130and flex-to-driver fan-out 139 also can have wire electrical contactsthat are disposed only in staggered configurations.

FIG. 8 illustrates a wire pattern in accordance with one embodiment ofthe present invention. Fan-out 150 can include wires designed toaccommodate (1) the maximum specified impedance for the signalstransmitted through the wires, and (2) the surface area available fordisposition of fan-out 150 on pixel activation substrate 152. Toaccommodate these factors, the wires of fan-out 150 can have widths thatvary from wire to wire and/or that vary along the same wire.

The resistance of a wire can be determined based on the followingequation:

$\begin{matrix}{R = \frac{\rho\; L}{A}} & {{EQ}.\mspace{14mu} 1}\end{matrix}$where ρ represents the resistivity of the wire material, L is the lengthof the wire, and A is the cross-sectional area of the wire. Thus, byvarying any one of these variables, e.g., the length or cross-sectionalarea of a wire, the resistance of the wire also can be varied.

As shown in FIG. 8, fan-out 150 can include wires having widths thatvary from wire to wire. It may be desirable to design wires to be ofnarrower widths when the signals transmitted on the wires do not need totravel, a long distance from a flex to driver 154 and/or the narrowerwidths can still accommodate the maximum specified impedances of thesignals transmitted along the wires. Similarly, it may be desirable todesign wires to be of wider widths when the signals transmitted on thewires need to travel a long distance from the flex to the driver and/orthe wider widths are needed to accommodate the maximum specifiedimpedances of the signals transmitted along the wires. Since one or moreembodiments of the present invention can include flex-to-driver fan-outwires having variable lengths, the wires of those embodiments can havewidths that vary from wire to wire.

Also shown in FIG. 8, fan-out 150 can include wires having widths thatvary along the same wire. For example, each wire A-C has a width thatvaries along the length of the wire. When there is more space availableon substrate 152 for the wires to be disposed, the width of wires A-Ccan be wider. However, when there is less space available (e.g., due tothe size of driver 154 or the layout of components on substrate 152),the width of the wires can be reduced. Advantageously, the resultingvariable width wires can have smaller effective resistances than thoseof wires having a constant width limited by the space available at onlycertain portions of the wires.

FIG. 9A illustrates prior aft wires used in conventional flex and driversub-assemblies, such as sub-assembly 10 of FIGS. 1A-1B. Each of priorart wires 160, 162 can have electrical contact 164, 166 disposed at theend of the wire for coupling to another electronic device. Adjacentwires 164, 166 can be separated by distance t. Typically, each wire 160,162 can have the same nominal cross-sectional shape with the samenominal height and width T. Each wire 160, 162 also can have the samenominal length and resistivity, thereby resulting in the same nominalresistance (R_(NOM)). In some conventional flex and fan-out designs,both prior art wires 160, 162 may he used to transmit the same power ordata signal. As described in greater detail below, however, the use oftwo identical wires to transmit the same signals can be less efficientthan one or more embodiments of the present invention.

FIGS. 9B-9D show illustrative composite wires in accordance with one ormore embodiments of the present invention. Composite wires 170 can besimilar to prior art wires 160, 162, except that each composite wire 170can transmit the same energy flux as multiple prior art wires 160, 162with less resistance. For example, each composite wire 170 can havetwice the width (2T) of prior art wire 160 or 162. All other factorsbeing nominally the same, the nominal resistance of composite wire 170can be half that of either prior art wire 160 or 162 (i.e., R_(NOM)/2).Furthermore, composite wire 170 can occupy less space than that occupiedby prior art wires 160, 162 in total (i.e., 2T v. 2T+t). Thus, in flexesand fan-outs in which prior art wires 160, 162 are used to transmit thesame power or data signal, the prior art wires can be replaced withcomposite wires 170 for more efficient use of space and/or for lessresistance. For example, composite wire 170 can be used to transmitsignals for a longer distance with less than or equal to the resistanceof prior art wires 160, 162. Furthermore, because less space is occupiedby composite wire 170, flexes can be narrower and less space can beoccupied by fan-outs.

In the embodiments illustrated in FIGS. 9B-9D, each composite wire 170can have multiple electrical contacts disposed at the end of each wireto emulate the electrical contacts from multiple prior art wires. Eachelectrical contact can be coupled to a complementary electrical contacton an electronic component, using, e.g., anisotropic conductive films.Electrical contacts 172-176 can be arranged in a side-by-sideorientation as in FIG. 9B, a stacked orientation as in FIG. 9C, in astaggered orientation as in FIG. 9D, or any combination thereof.

FIG. 10 shows illustrative electronic devices in which flex and driversub-assemblies of the present invention can be incorporated. Forexample, the sub-assemblies of the present invention can be incorporatedin media player/recorder 130, cellular telephone 140, touch-sensitiveelectronic device 150, or any combination thereof. Media player/recorder130 can have a display and playback audio and visual data. One exampleof a media player/recorder is a portable media player similar to thatsold under the trademark iPod™ by Apple Computer, Inc. of Cupertino,Calif. Touch-sensitive electronic device 150 can include electronicdevices that can accept user input by sensing the touch or proximity ofa user's body part, a stylus, or a digital pen through, e.g., atouch-sensitive display. Touch sensitive electronic device 150 caninclude, for example, personal digital assistants, hand-held gamingdevices, laptop computers, or tablet PCs.

The present invention also can be incorporated in any electronic devicein which a compact flex and driver sub-assembly may be desirable. Forexample, the electronic device can be any portable, mobile, hand-held,or miniature consumer electronic device. Illustrative electronic devicescan include, but are not limited to, music players, video players, stillimage players, game players, other media players, music recorders, videorecorders, cameras, other media recorders, radios, medical equipment,calculators, cellular phones, other wireless communication devices,personal digital assistants, programmable remote controls, pagers,laptop computers, printers, or any combination thereof. Miniatureelectronic devices may have a form factor that is smaller than that ofhand-held devices. Illustrative miniature electronic devices caninclude, but are not limited to, watches, rings, necklaces, belts,accessories for belts, headsets, accessories for shoes, virtual realitydevices, other wearable electronics, accessories for sporting equipment,accessories for fitness equipment, key chains, or any combinationthereof.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration. Alternative embodiments of thosedescribed hereinabove also are within the scope of the presentinvention.

Combinations of the above-described embodiments of the present inventionor portions thereof may be provided in one electronic device unit. Forexample, while FIG. 3 illustrates a display assembly having wires routedunderneath the display driver, other embodiments of the presentinvention, such as the assemblies of FIGS. 2A-2B, also can havesimilarly routed wires.

While the above described embodiments have illustrated the flex anddriver sub-assemblies of the present invention in the context of displayassemblies, the principles of the present invention also can be appliedto flex and driver sub-assemblies in any device or context.

The above described embodiments of the present invention are presentedfor purposes of illustration and not of limitation, and the presentinvention is limited only by the claims which follow.

What is claimed is:
 1. An assembly for operatively coupling a flexiblecircuit to a driver, the assembly comprising: a substrate for attachmentof the flexible circuit and the driver, the substrate having a substrateedge; a flexible circuit having multiple edges and at least partiallycovering a portion of the substrate edge, the flexible circuit attachedto the substrate; a first set of wires emanating from a first edge ofthe flexible circuit, the first set of wires disposed on the substratefor operatively coupling the flexible circuit to the driver; a secondset of wires emanating from a second edge of the flexible circuit, thesecond set of wires disposed on the substrate for operatively couplingthe flexible circuit to the driver, wherein at least a portion of afirst wire of the first set of wires is disposed on the substrate in atwo-dimensional pattern, such that the first wire has a non-linearconfiguration, wherein at least a portion of the flexible circuit ispositioned in-line with a longitudinal axis of the driver, and whereinthe width of the flexible circuit is less than the width of the driver.2. The assembly of claim 1, wherein a second wire of the first set ofwires has multiple electrical contacts positioned on a terminationregion of the second wire.
 3. The assembly of claim 1, wherein a secondwire of the first set of wires has a variable width along its length. 4.The assembly of claim 3, wherein at least a portion of a first wire ofthe second set of wires is disposed on the substrate in atwo-dimensional pattern with a non-linear configuration.
 5. The assemblyof claim 1, wherein the first wire has a width that is different thanthat of a second wire of the first set of wires.
 6. The assembly ofclaim 1, wherein the assembly has a form factor suitable forincorporation within a hand-held electronic device.
 7. The assembly ofclaim 1, wherein the substrate comprises a substrate suitable forelectronic displays.
 8. A method for manufacturing an assembly with adriver, the method comprising: providing a substrate, the substratehaving a substrate edge; providing a flexible circuit having multipleedges and at least partially covering a portion of the substrate edge,the flexible circuit coupled to the substrate; disposing a first wire onthe substrate emanating from a first edge of the flexible circuit foroperatively coupling a flexible circuit to the driver, wherein at leasta portion of the first wire is disposed on the substrate in atwo-dimensional pattern, such that the first wire has a non-linearconfiguration; and disposing a second wire on the substrate emanatingfrom a second edge of the flexible circuit for operatively coupling aflexible circuit to the driver, wherein at least a portion of the secondwire is disposed on the substrate in a two-dimensional pattern, suchthat the second wire has a non-linear configuration, and wherein aportion of the flexible circuit is positioned in-line with alongitudinal axis of the driver.
 9. The method of claim 8, wherein thewidth of the flexible circuit is less than the width of the driver. 10.The method of claim 8, wherein the second wire has a variable widthalong its length.
 11. The method of claim 8, wherein the second wire hasa width that is different than that of the first wire.
 12. Displaycircuitry for operatively coupling a flexible circuit to a driver andfor operatively coupling the driver to pixel activation components, thedisplay circuitry comprising: a substrate for attachment of the flexiblecircuit, the driver, and the pixel activation components; a first set ofwires disposed on the substrate for operatively coupling the flexiblecircuit to the driver, the first set of wires emanating from a firstedge of the flexible circuit; and a second set of wires disposed on thesubstrate for operatively coupling the flexible circuit to the driver,the second set of wires emanating from a second edge of the flexiblecircuit, wherein the substrate has an area to be completely covered bythe driver, wherein at least a portion of a first wire of the first setof wires is disposed in the area, and wherein the width of the flexiblecircuit is less than the width of the driver.
 13. The display circuitryof claim 12, wherein the first and second set of wires have non-linearconfigurations.
 14. Display circuitry for operatively coupling aflexible circuit to a driver, the circuitry comprising: a substrate forattachment of the flexible circuit and the driver; a first set of wiresdisposed on the substrate for operatively coupling the flexible circuitto the driver, wherein the first set of wires emanates from a first edgeof the flexible circuit; and a second set of wires disposed on thesubstrate for operatively coupling the flexible circuit to the driver,wherein the second set of wires emanates from a second edge of theflexible circuit, and wherein the substrate has an area to be completelycovered by the driver, and wherein at least a portion of a first wire ofthe first set of wires is disposed in the area.
 15. The displaycircuitry of claim 14, wherein at least one of the first set of wires isdisposed on the substrate in a non-linear configuration.